My invention relates generally to foldable pocket knives and the like, and more particularly to a knife having means for assisting the movement of one or more knife blades from a closed position to an open position and the reverse.
In general terms pocket knives and the like, wherein a blade or blades are stored within a handle during non-use, require a greater force to open when the blades are larger and larger. This is brought about the need to overcome a stiff back spring of such knives. Accordingly, for large folding knives, means have occasionally been provided to mechanically assist pivoting the blade or blades from a closed position within the handle to an open position generally causing the blade to extend from the handle to an inline relationship.
One knife construction with means for assisting in the movement of a blade is that described in U.S. Pat. No. 364,414, issued to C. Hollweg on June 7, 1887. In this patent a blade has a usual aperture for a pivot together with a second aperture for engagement with a turning mechanism. Further, there is a turning plate which is operated by a folding key-type turning handle. The turning handle has a pair of recesses which cooperated with lugs on a locking plate when the turning handle is folded against the knife handle, i.e., the locking plate on the handle.
Another patent having a blade-assisting mechanism is U.S. Pat. No. 633,854 issued to Ernst Kuhn on Sept. 26, 1899. In this patent, a single blade is shown with the blade pivot extending perpendicularly from the exterior of the knife handle. The blade appears to be nonrotatably attached to the pivot. Exterior of the handle, a bent wire-like key passes transversely through the pivot. The key can be folded back against the surface of the knife handle whereby it engages a knobbed projection on the knife handle. This locking feature, as in the first-cited patent, is designed to prevent inadvertent closing of the knife blade during use. As well, such locking prevents inadvertent opening of the knife.